A demonstration of an automotive self-radiative cooling coating jointly developed by Nissan Motor Co., Ltd. and ラディクール was opened to the public at Haneda Airport, demonstrating how heat is released into space through the coating film and the resulting difference in vehicle surface temperature. The coating is currently available only in white, but the surface temperature difference between the demonstration vehicle and a standard vehicle reached approximately 7°C.
The automotive self-radiative cooling coating is a coating material that uses “metamaterial” technology to artificially achieve radiative cooling. It is designed to suppress increases in temperatures inside and outside the vehicle by releasing thermal energy from the coating film into space. The coating contains particles that emit electromagnetic waves at specific wavelengths, converting the energy into electromagnetic waves at wavelengths that are not absorbed by the atmosphere to produce a cooling effect.
In the demonstration at Haneda Airport, the coating was applied to vehicles operated by ANA Airport Services Co., Ltd. with the cooperation of Nissan Motor Co., Ltd. and Japan Airport Terminal Co., Ltd. A comparison of the coated and standard vehicles found that the standard vehicle had a surface temperature of 43.5°C, versus 36.6°C for the vehicle with the self-radiative cooling coating, confirming a temperature difference of approximately 7°C.
A company representative explained that one current challenge is that the film tends to become thick during the air-spray application and clear-coat overcoating processes, making the coating difficult to apply to mass-produced vehicles. Adoption of the coating is currently under consideration for specialty and commercial vehicles. Its effectiveness may also decline in winter, while radiative cooling energy is expected to have a greater effect in summer.
Future plans include developing colors other than white. The coating is also attracting attention as part of efforts toward carbon neutrality because it may lower room temperature and reduce energy consumption.